In 1824, Joseph Aspdin took out a patent for the manufacture of the world's first portland cement. The name came from the color of the material, which resembled stone from the Isle of Portland. The cement was definitely superior to the cements that had preceded it, and was the forerunner of the cement used for concrete today. Aspdin's formula was improved upon in 1845, when Isaac Johnson raised the temperature at which the cement is fired.
Several people contributed to the development of reinforced concrete. Jean-Louis Lambot constructed rowboats out of a wire matrix plastered with mortar in 1848; Joseph Monier built large plant tubs using the same process, which he patented; William Wilkinson took out a patent in 1854 for a method of reinforcement using hoop iron.
Francois Hennebique was a French engineer that pioneered the use of structural concrete--he patented a complete building system in 1892. Hennebique's system is essentially the same system that is used today. Eugene Freyssinet discovered the value of mechanical vibration for compacting concrete, and also engineered a system for prestressing concrete.